Pin pandas yet again :panda_face: `test_icon` fails again with pandas=2.2.2

[valeriupredoi]

Description

Tests are failing with the same issue we had in the past, described by @schlunma in https://github.com/ESMValGroup/ESMValCore/pull/2305 and with an original bug report in pandas at https://github.com/pandas-dev/pandas/issues/57002 - they just switched the milestone for that for 2.2.3 apparently!

---

Before you get started

Checklist

It is the responsibility of the author to make sure the pull request is ready to review. The icons indicate whether the item will be subject to the 🛠 Technical or 🧪 Scientific review.

• [x] 🛠 This pull request has a descriptive title and labels
• [x] 🛠 Any changed dependencies have been added or removed correctly
• [x] 🛠 All checks below this pull request were successful

---

To help with the number pull requests:

• 🙏 We kindly ask you to review two other open pull requests in this repository

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 94.28%. Comparing base (e2c68e7) to head (52073c5).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #2394 +/- ## ======================================= Coverage 94.28% 94.28% ======================================= Files 246 246 Lines 13511 13511 ======================================= Hits 12739 12739 Misses 772 772 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[valeriupredoi]

thanks a lot, Manu! I too agree with fixing the test rather than pinning the ninja bears, but I didn't have the will to look at it closer - good call you did, you mind opening a PR with the fix pls, bud? :beer: In the meantime this will do :panda_face: